Skip over navigation

 

Study on Mechanics behavior of Magnetoelectric Laminate Composites based on surface-effect Modeling and Experimental Characterization

Daining Fang (College of Engineering, Peking), Faxin Li (College of Engineering, Peking University), Feng Hao (), Hao Zhou (College of Engineering, Peking University), Jing Ma (College of Engineering, Peking University)

Prager Medal Symposium in honor of George Weng: Micromechanics, Composites and Multifunctional Materials

Tue 4:20 - 5:40

MacMillan 117

Magnetoelectric (ME) laminate composite is a kind of intellectual material with the ability of conversion between electric and magnetic signals which demonstrates significantly enhanced ME effect over single-phase ME material. From the theoretical viewpoints, we developed a surface-effect model for nano-scale ME bilayer and an extended plate theory for ME laminates. The former model introduces surface/interface effect into the ME coefficient calculation of flexural magnetostrictive-piezoelectric bilayers. The results show that both flexural deformation and interface misfit strain have notably impact on the ME voltage coefficient. Owing to residual surface tension, the size dependence of ME voltage coefficient is found when the thickness of bilayer reduces to nano-scale. The second model is an extension of classic laminate plate theory to the multi-field coupling case. A universal equation of ME coefficients can be derived by this theory which has the ability to predict ME properties of ME composites with complex laminate structures. Coupled stretching-bending deformation mode is considered in this model. The calculating results show that both stretching and bending modes can induce significant ME effect and that different structured ME laminate thin films have different sensibility to the thickness and properties of substrates. For the experimental aspect, a multi-field nanoindentation apparatus is developed to probe the nano/micro-scale magneto-electro-mechanical coupling properties of the ME laminate composite or single phase multiferroic materials. This device can obtain the load-depth curves under various electrostatic field and/or magnetostatic field. The quasi-static indentation test on La0.7Sr0.3MnO3/0.33PIN-0.35PMN-0.32PT (350nm/0.4mm) indicates that the mechanical behavior, such as the apparent modulus, indentation hardness and energy loss during a load-unloading process, of the layered thin film can be controlled by electric field and magnetic field.